Field
Embodiments of the present disclosure generally relate to methods for forming low resistivity interconnects. More specifically, embodiments described herein relate to ultra-thin laminar intermetallic films suitable for use as interconnect structures in semiconductor manufacturing processes.
Description of the Related Art
Integrated circuits have evolved into complex devices that can include millions of components, such as transistors, capacitors, and resistors on a single chip. The evolution of chip design continually requires faster circuitry and greater circuit densities. The demand for greater circuit densities necessitates a reduction in the dimensions of the integrated circuit components.
As the dimensions of the integrated circuit components are reduced, the materials used to fabricate such components increasingly affect the performance of the components. For example, in a device with a reduced feature width, device current typically remains constant or increases, which results in an increased current density on the features. Higher device densities and faster operating frequencies have created demand for a suitable material with low resistivity values compared to conventionally utilized aluminum for forming interconnect structures.
Copper materials have also been used in conventional interconnect schemes because copper generally exhibits relatively low resistivity and high conductivity. However, with advanced technology nodes, such as sub-10 nm node architectures, the resistivity of copper increases as line widths shrink below about 50 nm and approach the mean free path of electrons in copper (39 nm). The increase in resistivity may be due, at least in part, to electron scattering at the surface of the line and at grain boundaries of the copper material. In addition, barrier layers are utilized with copper interconnects to prevent undesirable diffusion of the copper into underlying materials, such as low-k materials. However, barrier layers may undesirably increase the resistivity associated with the copper interconnect scheme. As such, copper materials may not be suitable for advanced technology nodes.
Accordingly, what is needed in the art are materials and methods for forming contact and interconnect structures.